Melt chocolate and 1 stick butter in double boiler.,Cream 1 stick butter with 2 cups of sugar.,______,Add eggs, one at a time and mix well, then add vanilla and chocolate mixture. Sift and fold in flour.,Pour into a greased 9 x 13-inch pan. Spread evenly, then bake 20 to 25 minutes at 350°.,Do not overcook.